The invention relates to cross country ski bindings with a support element attachable directly to a ski for engaging a forwardly extending sole extension and being liftable from the ski at its rearward end.
Cross country ski bindings are known (German Utility Model No. 7,505,336) with forward lateral jaws, a strap articulated to the lateral jaws, said strap lying over the forward part of the boot sole in one functional position and being lockable in this position. However, such bindings have the particular disadvantage of being boot-dependent, i.e., the lateral centering of the boot sole requires a plurality of bindings for different boot sizes as well as different designs for right and left boots. Therefore, such bindings are cumbersome, costly, and to a certain extent, too heavy. The sidewise projection of the lateral jaws beyond the edge of the ski also has a disadvantageous effect upon the guidance of the ski.
Cross country ski bindings have also been contemplated wherein the above-mentioned disadvantages are eliminated by a forward extension of the boot sole, thereby providing freedom of design for the cross country ski binding by virtue of this boot sole extension, and permitting use of only one binding for right and left boots as well as for different boot sizes. In this design, the boot sole is lockable by means of a cross bolt. However, operation of said bolt is troublesome and uncomfortable such that it is impractical and inconvenient for bindings intended for normal skiers.
An important object of the invention is to provide a binding of the simplest possible construction, said binding also being inexpensive and light in weight, which binding is independent of the boot sole and does not project sidewise beyond the ski, in addition to being easily attached to and removed from the ski. In particular, a reliable grip must be provided even when there is snow on the boot sole.
This object is obtained according to the invention by providing that the sole extension is automatically latchable and/or lockable under spring tension to the ski.
The following advantages are gained by the above-noted basic arrangement of the invention:
It is possible to step comfortably into the binding, without the skier having to bend over. A reliable grip on the boot is ensured, even with snow on the sole. According to alternative proposed embodiments, the boot sole can be used directly as a holding element, or can form a part of the latching device, thus allowing minimal structural cost. Furthermore, since the axis of rotation running crosswise relative to the longitudinal axis of the ski and boot, around which the boot rotates when lifting the extension from the ski, can be located ahead of the toe part of the boot, a gentle, elastic rolling of the boot on the ski is possible, ensuring sufficient freedom of movement and blood flow to the toe part of the foot. Since only the sole extension is gripped by the binding, the boot sole itself is freely movable and unaffected by friction. The simple design of the cross country ski binding ensures low weight, which is particularly advantagous in racing.
In order to make it possible to put on and take off the ski easily, according to a further feature of preferred embodiments of the invention, the binding is so designed that the boot can be brought into the latching and/or locking position automatically by sliding it lengthwise along the ski. According to some preferred embodiments of the invention, this sliding motion is advantageously performed by moving the boot and sole forward from the rear. However, other preferred embodiments are also contemplated which will allow this sliding motion to be carried out from the front or from above. Advantageously, the latching device is designed so that it effects automatic latching of the sole extension in the supported position (in use skiing position) of the boot against the supporting element, but prevents spontaneous unlatching of the latched boot. Furthermore, the movable latching element is preferably designed as a handle for releasing and/or fastening the latching devide manually or by means of the ski pole. In addition, those latching devices contemplated by the invention are particularly advantageous which latch reliably with snow on the sole or which can be adjusted and/or tightened automatically after the snow on the sole has melted.
In certain preferred embodiments, a latching device is provided which pulls the boot into the support position during the closing process, thus reinforcing the pulling and/or pushing of the boot into the latched and/or locked position.
The present invention contemplates various embodiments, wherein the latching device may be located at any point between the boot sole extension and the supporting element. However, in especially preferred embodiments, it is simplest and most advantageous to install it between the boot extension and a lower part of the supporting element which is integral with the ski. However, the latching device can also be mounted on the upper side or on one or both sides of the boot sole extension according to other contemplated embodiments. When a lever arm is used, for example, in the form of a leaf spring or a wire spring, the swivel axis of the lever arm may run crosswise to and/or in the longitudinal direction of the ski and/or boot, or can run perpendicularly to the surface of the ski according to various preferred embodiments contemplated by the present invention.
In yet other contemplated embodiments an especially simple and advantageous embodiment of the invention consists in using a sole insert embedded in the boot sole as a latching element, especially in the form of an inserted sheet of spring steel. Such a sole insert, known per se in other positions in a ski boot of a type different than that contemplated by the present invention, on the one hand stiffens the boot sole with the boot sole extension and, especially if simultaneously turned outward as a latching element, can be used as a lever arm to release the latching device, thus accommodating releasing of the binding to remove the ski.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.